For example, in a biaxial actuator, in which an objective lens is loaded, of an optical disk recording and/or reproducing apparatus, the objective lens needs to be mounted after inclination thereof is adjusted to become the reference state in radial and tangential directions with respect to a disk surface while the biaxial actuator is not being driven. Namely, such adjustment and mounting enables the driving performance on the objective lens by the biaxial actuator to be the most efficient.
As the above-described biaxial actuator, the applicants of the present invention previously proposed relevant technology disclosed in Japan Utility Model Application Laid-Open No. Sho-62-150723 and Japan Patent Application Laid-Open No. Hei-9-251653. Specifically, in the former application, as shown in FIG. 5, a spherical shaft portion 45 (convex-spherical surface), a spherical bearing portion 46 (concave-spherical surface), and adjusting screws 35 and 36 are used to adjust inclination in the radial and tangential directions of an objective lens provided in a biaxial actuator 20 with respect to a disk surface. Also, in the latter application, as shown in FIG. 6, it is arranged that the similar adjustment is performed by first and second plates.
Specifically, in a state where the above-described biaxial actuator is not being driven, a light beam is irradiated through the objective lens onto a surface of a disk for adjustment, and then the reflected light beam or the like is detected to adjust the inclination of the objective lens to be in a reference state in radial and tangential directions with respect to the disk surface. Then, in the state where such adjustment has been done, the convex-spherical surface and the concave-spherical surface are fixed together with the adjusting screws or the like. Alternatively, the first and second plates are joined together using solder or the like to determine the reference state of the objective lens.
However, in the above-described biaxial actuators, there are required a plurality of components such as the convex-spherical surface and concave-spherical surface, or the first and second plates. In addition, with respect to surfaces between those components, it is required to perform surface processing in order that the adjustment is performed without difficulties and the joining using solder or the like is efficiently performed. As a result, there is a possibility that the cost of such components or the like may increase. Further, when the joining is performed by using solder or the like, there is also a great possibility that, for example, the optical components such as an objective lens are contaminated if the solder or the like is scattered.
The present application has been made in view of the above-described problems, and the problems to be solved are that: in conventional devices there has been required a plurality of components such as the convex-spherical surface and concave-spherical surface, or the first and second plates; then there has been a possibility of increase in the cost of those components in order to perform surface processing or the like on surfaces for joining; and there is further a possibility of contamination of the optical components such as the objective lens or the like if solder or the like is scattered when joining is performed.